Foxy Green Foxbody Build

Let's have an actual discussion amongst members, I know a lot of you don't like to discuss stuff because "internet experts".

I know the gauge is just a guide, or reference, and helps paint a larger picture, but for piece of mind can I get your guys thoughts on AFR.

Id consider these "target" numbers if I had to paint the picture even though it's more dynamic than this:

13.5 cold idle/ warm up
14.5 normal idle
14.5 light cruising
13.0 moderate acceleration
12.0 WOT
17.0 deceleration

Ready, go
 
89 Fox 427 said:
Let's have an actual discussion amongst members, I know a lot of you don't like to discuss stuff because "internet experts".

I know the gauge is just a guide, or reference, and helps paint a larger picture, but for piece of mind can I get your guys thoughts on AFR.

Id consider these "target" numbers if I had to paint the picture even though it's more dynamic than this:

13.5 cold idle/ warm up
14.5 normal idle
14.5 light cruising
13.0 moderate acceleration
12.0 WOT
17.0 deceleration

Ready, go
Click to expand...
None of that bothers me. AFR gauges are a trap. You're only getting a partial picture of what's happening. Good tool to avoid something big being wrong, not something to obsess over every moment. Of course it's going to lean out on deceleration and your driving numbers look fine.
 
89 Fox 427 said:
Let's have an actual discussion amongst members, I know a lot of you don't like to discuss stuff because "internet experts".

I know the gauge is just a guide, or reference, and helps paint a larger picture, but for piece of mind can I get your guys thoughts on AFR.

Id consider these "target" numbers if I had to paint the picture even though it's more dynamic than this:

13.5 cold idle/ warm up
14.5 normal idle
14.5 light cruising
13.0 moderate acceleration
12.0 WOT
17.0 deceleration

Ready, go
Click to expand...
Love engine tech discussions, definitely not any type of expert. I've had lots of problems I've had to figure out on my own and try to share info if I can. Try to have fun!
Anything specific you feel "stupid" (your words 🤷‍♂️) about that someone may be able to help with?
 
Just watched a vid where they moved from 12.5 to 13.3 on a 410w and gained a decent amount. But on the dyno, not street.
I would stick with 12.5, lol
 
89 Fox 427 said:
Let's have an actual discussion amongst members, I know a lot of you don't like to discuss stuff because "internet experts".

I know the gauge is just a guide, or reference, and helps paint a larger picture, but for piece of mind can I get your guys thoughts on AFR.

Id consider these "target" numbers if I had to paint the picture even though it's more dynamic than this:

13.5 cold idle/ warm up
14.5 normal idle
14.5 light cruising
13.0 moderate acceleration
12.0 WOT
17.0 deceleration

Ready, go
Click to expand...

Take that information, pack it in your back pocket for now.


Get your spark plug socket, and an extra set of plugs, and start pulling various plugs from each bank, note the cylinders. Learn to read them appropriately.

The plug will tell you exacly what's happening inside that boom fire hole. Or at least, lead you in a positive direction..
 
Mr. Breeze said:
Take that information, pack it in your back pocket for now.


Get your spark plug socket, and an extra set of plugs, and start pulling various plugs from each bank, note the cylinders. Learn to read them appropriately.

The plug will tell you exacly what's happening inside that boom fire hole. Or at least, lead you in a positive direction..
Click to expand...

This leads me to anther question that drives me nuts.

With the amount of idle time, how often I'm fucking with timing and carb settings, what do you suggest I do?

My plan is back to basics. Distributor plugged, 16 base timing. 18° limiter bushing, (34 total timing), hook up vacuum advance to manifold, change plugs. Drive the car for 5 miles or so, pull plugs.

Do I need more drive time, does this seem like a reasonable next step?
 
89 Fox 427 said:
This leads me to anther question that drives me nuts.

With the amount of idle time, how often I'm fucking with timing and carb settings, what do you suggest I do?

My plan is back to basics. Distributor plugged, 16 base timing. 18° limiter bushing, (34 total timing), hook up vacuum advance to manifold, change plugs. Drive the car for 5 miles or so, pull plugs.

Do I need more drive time, does this seem like a reasonable next step?
Click to expand...

I like it, except for the 5 mile deal. Fresh plugs, warm engine, make relatively strong hit, shut down immediately, read plugs.
 
89 Fox 427 said:
This leads me to anther question that drives me nuts.

With the amount of idle time, how often I'm fucking with timing and carb settings, what do you suggest I do?

My plan is back to basics. Distributor plugged, 16 base timing. 18° limiter bushing, (34 total timing), hook up vacuum advance to manifold, change plugs. Drive the car for 5 miles or so, pull plugs.

Do I need more drive time, does this seem like a reasonable next step?
Click to expand...
You'll need a new plug each wot pull. Find a spot with nobody around, do your wot run and shut off immediately, coast to a stop and remove plug and read, ear doctor light helps or cut threads off. Any octane boost etc will change plug color also.
Not beating a dead horse here but I wouldn't be messing with vacuum advance or weights til the carb is figured out
 
BOSS#1540 said:
You'll need a new plug each wot pull. Find a spot with nobody around, do your wot run and shut off immediately, coast to a stop and remove plug and read, ear doctor light helps or cut threads off. Any octane boost etc will change plug color also.
Not beating a dead horse here but I wouldn't be messing with vacuum advance or weights til the carb is figured out
Click to expand...
Why. Timing changes everything carburetor related. That's the first thing you should get figured out. Am I missing something?
 
89 Fox 427 said:
Why. Timing changes everything carburetor related. That's the first thing you should get figured out. Am I missing something?
Click to expand...
Try to work on one thing at a time. For example, don't make a carb adjustment AND a timing adjustment because you won't know what did what.
If the carb is fucked it'll do damage without you noticing before timing will.
This is why I suggested locking the distributor at 28°ish, it eliminates any vacuum advance/ springs, weights, bushings issues. It's safe, too little advance will heat up exhaust valves and turn headers red, too much advance, you'll know. I ran locked at 31-32° for over 15 years on the street, tried all the shit yer doing with bushings and gave up, man pedal car also, same as you). My dizzy has no vacuum advance port. Maybe I read wrong but thought yours could be locked out as well.
When you're happy with the carb and it's tune is safe then dial in the timing, tweak carb, then play with advance, etc. Your plug will tell you about your timing also. Plug reading is an art and nice to have someone with experience to help explain. Tune for best mph in 1/4 mile with jetting, then richen one size for safer street driving, same with timing, find best then back off a degree or two on the street.
 
The last thing I want to do is cause you more work. If you're happy and confident the distributor isn't causing you any headaches, timing or vacuum issues then carry on. My suggestion of locking it out was just to help eliminate possible problems.
Do you know anyone with a proven carb you could try
 
BOSS#1540 said:
The last thing I want to do is cause you more work. If you're happy and confident the distributor isn't causing you any headaches, timing or vacuum issues then carry on. My suggestion of locking it out was just to help eliminate possible problems.
Do you know anyone with a proven carb you could try
Click to expand...

I'm not opposed to locking it out, but I was getting kick back at 24 degrees last year so that seems out of the question on this car.
 
At risk of stating the obvious, when checking plugs always look at the same plug(s). Or else look at all of them. I fooled myself by looking at several different plugs assuming they would all look the same, when I was about 18 and trying to figure out my 2x4 tunnel ram, one was always dark and one was always light, made no sense. Duh! :facepalm:
 
Your saying the timing is all over the place whats the timing light tell you if your mark is jumping then you have issues .
At this time I would not worry about AFR just get the carb dialed in for good idle nice transitions from closed to open throttle and take it for a nice drive do a few pulls on it get it home look at the plugs color that will tell you alot .
You will get it figured out you have good advice coming from all the guys on here .
Do what works for you your learning as you go
 
How does the engine feel right now? As in, throttle response, power, etc?

Pinging? Popping on decel?

We can all sit back and guess shit from over here, but the ball is in your court now to tune it. Reading plugs will help with timing as well. Nothing wrong with locking it out for now, until you learn more about it, then you can play with the curve.

Personally, I think it's over carbed, but I don't know enough the cam and head combo to really make that call.
 
Mr. Breeze said:
How does the engine feel right now? As in, throttle response, power, etc?

Pinging? Popping on decel?

We can all sit back and guess shit from over here, but the ball is in your court now to tune it. Reading plugs will help with timing as well. Nothing wrong with locking it out for now, until you learn more about it, then you can play with the curve.

Personally, I think it's over carbed, but I don't know enough the cam and head combo to really make that call.
Click to expand...

I agree I think it's over carbed. The car idles all the time though so I don't really have real world answers. I need to stop fuckin with timing and run the thing and evaluate.

I put the 18 degree bushing in it. Going to back base timing to 16. I'd like to put bigger air bleeds in it but I don't have any. 78 or 80 should allow me to get the mixture screws in the 1.5 turn window where they should be.
 
The tip in is fucked off. I have to blip the throttle to take off with the clutch, if I ease into throttle it goes lean. I need to do a search for vacuum leaks or something. The accelerator pump seems to be adjusted right at zero lash so I don't know what else would cause that stumble.

Anther symptom (maybe) is light throttle in cold start to try and keep it running and it leans out and dies. Maybe the carb is gummed up
 
89 Fox 427 said:
I'm not opposed to locking it out, but I was getting kick back at 24 degrees last year so that seems out of the question on this car.
Click to expand...
I never had an issue with it starting when hot or any other time. But I did build this thing with less than recommended clearances to prevent end gases to run on pump 93 at 12.8:1.
That can make a difference, even though two engines seem similar on details.
Was it locked at 24 last year?
 
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